"We are all of us, five minutes from death"

" I learned starkly that lack of breath does not feel like anaesthesia or sleep; it is like death"

" I know of no human experience that produces such a spasm of uncontrolled panic as does breathlessness"

" The folds and convolutions of the lungs result in a surface area forty times larger than the skin's area and large enough to carpet a small apartment"

" On an average day our lungs move enough air in and out to fill a medium size room or blow up several thousand party balloons."

" Breathing is important ! If you've ever doubted it try holding your breath for the next 10 minutes... "

Four Terms that are not equal... Breathing External respiration internal respiration cellular respiration

Breathing is... … the entrance and exit of air into and out of the lungs … consists of inspiration (breathing in) … and expiration (breathing out)

External Respiration is... … the exchange of gases ( O 2 and CO 2 ) between air and the blood. … lower temperature (lungs) … higher pH (7.4)

Internal Respiration is... … the exchange of gases ( O 2 and CO 2 ) between blood and tissue fluid. … higher temperature (tissues) … lower pH (7.35)

Cellular Respiration is... … the production of ATP within the cell. … requires O 2 … gives off CO 2 as a waste product that must be returned to lungs to rid of (external respiration)

Respiratory Tract Right lung has three lobes Left lung has two lobes Fill entire thoracic cavity from pharynx to diaphragm

As air moves in it is... Filtered (hair in nostrils, cilia in trachea) Warmed (by surrounding blood vessels) Moistened (by wet surfaces of air passages)

You should be able to identify and give functions for the... larynx trachea bronchi bronchioles alveoli diaphragm and ribs pleural membranes thoracic cavity Eustachian tubes

The larynx... Voice Box Triangular box … projects in front of neck as Adam’s apple. Glottis is opening covered by epiglottis during swallowing of food If food passes epiglottis into larynx, reflex coughing usually expels it. Contains vocal cords

The trachea... Air tube from larynx to bronchi Held open by C- shaped cartilaginous rings Contains cilia projecting from epithelium Cilia keep lungs clean by sweeping debris toward throat. Mucus secreted to embed and transport debris. If blocked … tracheotomy may be performed.

The Bronchi... Trachea divide into two bronchi (sing. Bronchus) Cartilage rings keep tube open Lead to right and left lungs Branch into smaller units termed bronchioles. Asthma is constriction of bronchioles, which reduces or prevents air movement. Terminate in air pockets or sacs termed alveoli.

The Alveoli (a case of structure matching function) Functional unit of the lungs since this is where gas exchange actually occurs. Single layer of squamous epithelium surrounded by blood capillaries. Approximately 300 million alveoli have total cross-sectional area of m 2 … This is about 40 times the surface area of the skin. I.R.D.S. (lack of lipoprotein surfactant)

The Diaphragm and Ribs Diaphragm is a layer of dome shaped muscle that makes up the base of the thoracic cavity. Functions to increase size of thoracic cavity thereby decreasing pressure, when it contracts. The ribs, hinged to the vertebral column at the back and the sternum at the front, make up the top and sides of the thoracic cavity. Very much a part of the breathing process.

The Pleural Membranes The lungs are covered by the pleural membranes, one of which covers the lungs themselves, and the other that lines the chest cavity. Function is to hold lungs to thoracic wall which creates a seal to reduce pressure in the lungs. Inflammation is called pleurisy.

The pleural cavity in certain conditions may be filled with air (pneumothorax), blood (hemothorax), or pus. Any opening of the wall, whether done for surgical purposes or by accident from a bullet or knife wound, will cause the lungs to collapse due to the pneumothorax created.

The Breathing Mechanism... Could you describe the interaction of lungs, pleural membranes, ribs, and diaphragm during inhalation and exhalation?